1. Technical Field
The present invention relates to a sensor element, a manufacturing method of the sensor element, a sensor device, and an electronic apparatus.
2. Related Art
As sensor elements, for example, angular velocity sensors (vibration gyro sensors) that detect physical quantities such as angular velocities and acceleration used for vehicle body control in vehicles, self-location detection of car navigation systems, vibration control correction of digital cameras, video cameras, etc. (so-called camera shake correction) have been known (for example see Patent Document 1 (JP-A-2008-14887)).
For example, the angular velocity sensor disclosed in the patent document has a tuning fork including two arms and a connection part that connects one ends of the two arms. Further, in the angular velocity sensor disclosed in Patent Document 1, the turning fork is formed using a non-piezoelectric material, and a drive part and a detection part including a piezoelectric thin film inserted between a pair of electrodes are respectively formed in each arm.
In the angular velocity sensor disclosed in Patent Document 1, by applying a voltage to the pair of electrodes of the drive part, the arm is flexurally vibrated (driven). Further, under the drive condition, when the arm is subjected to an angular velocity around an axis line along the extension direction thereof, the arm bends in a direction orthogonal to the above described drive direction by Coriolis force, and electric charge in response to the amount of bending is detected from the pair of electrodes of the detection part. The angular velocity may be detected based on the detected charge.
Incidentally, the above described tuning fork having the two arms is generally formed by etching processing of a substrate. In this regard, it is difficult to make the dimensions of the tuning fork as designed due to etching anisotropy of the substrate, variations of processing process, or the like. Accordingly, the tuning fork may have an unintended shape and, even when the arm is not subjected to any angular velocity, the arm may bend in a direction different from the drive direction. If the electric charge generated from the pair of electrodes of the detection part as the arm bends, reduction in detection sensitivity is caused.
On this account, in the angular velocity sensor disclosed in Patent Document 1, one electrode of the pair of electrodes of the detection part is partially removed and the amount of charge output from the pair of electrodes of the detection part when the arm is not subjected to any angular velocity is adjusted.
However, in the angular velocity sensor disclosed in Patent Document 1, there has been a problem that the adjustment range of the amount of charge output from the pair of electrodes of the detection part is smaller, and, as a result, it may be impossible to perform desired adjustment.